Floor-surfacing machine



May 27, 1930. JACOBSON ET KL 1,760,832

FLOOR SURFACING MACHINE 4 Sheets-Sheet 1 Filed En 4. 192a I gag" M ATTORNEY FLOOR SURFAC ING MACHINE Filed Aug. 4, 1926 4 Sheets-Sheet 2 y a INVENTOR ax zw M A TTORNEI y 7; 1930- G. JACOBSON ET AL FLOOR SURFACING MACHINE Filed Aug. 4. 1926 4 Sheets-Sheet 3 NTOR 5 z m M; /w'

lJrATToRNEv May 27, 1930. G, JA OB ON E1 AL 1,760,832

FLOOR SURFAGING MACHINE Filed'Aug- I926 4 Sheets-Sheet 4 r I I XINVENTOH Patented May 27, 1930 UNITED STATES PATENT OFFICE GUSTAV JACOBSON AND GUNNAR R. RRI 'soiT, OF NEW YO N. Y., Ass IGNORs T0 SUPERIOR FLOOR SURFAGING MACHINE CORPORATION, OF NEW YORK, N. Y., A

CORPORATION OF NEW YORK FLOOR -SURFACING MACHINE Applicationfikd August 4, 1926. Serial No. 126,951.

This invention relates to floor surfacing machines, and aims to improve the construction and more particularly the operation of such machines.

5 The invention relates to the type of floor surfacing machine which consists of. a motor driven carriage provided at opposite ends thereof withtwo grinding drums which are rotated in opposite directions. In machines of this character now in use it has been found that irregularities in the floor surface set up small but sustained vibrations of the grinding drums which cause an objectionable ripple-like surface in the floor.

A particular Object of thepresent invention is to avoid such vibration of the grinding drums. In accordance with the invention, this result is obtained by mounting the drums in such manner that their weight 5 position is horizontal and whose length is equal to several times the radius of the drums. The pressure of the drums against the floor is regulated by applying the force of separate compression springs to these arms at points near the drums.

- A further object of the invention is to providea floor surfacing machine capable of operation close to .a wall.

The nature of the invention may best be understood from a detailed description of a' practical'flo-or surfacing machine embodying theinvention which is shown in the accomdrawings, in which-2 3 Fig. 1 is a side elevation of the machine;

holds them closely against the floor and Fig. 3 is an enlarged vertical transverse section of the machine taken on the line 3- 3 v of Fig. 1; Fig. 4 is a sectional detail showing the self-aligningbearings used at the ends of,

the drums;

Fig. 5 is an enlarged side elevation showing the parts of the machine utilized in regulating the pressure between the grinding. drums and the fiooryomitting the driving and steering mechanism and showing the platform of the machine sectioned on the line 5.--5 of Fig. 6; i a

Fig. 6 is a top view of the machine sectioned on the line 66 of Fig. 1;

Fig. 7 is a side elevation of the machine sectioned on its longitudinal axis; v I

1 Fig. 8 is a transverse section of the machine on the line 88 of Fig.7 and Fig. 9 is a transverse section of the ma-- chine on the line 9-9 of Fig. 7.

The machine illustrated includes a motor driven carriage 1O havinga platform 11 and depending side flanges 12, 12 betweenwhich are pair of traction wheels 13 andtwo steering wheels 14. The traction wheels 13 are driven from a motor-15 mounted on the 7 platform 11. Through a chain 16 the motor drives a cross-shaft 17 carrying a spur gear 18 meshing with. a similar spur gear 19 on a second cross-shaft 20. A worm 21 on the cross-shaft 2O drivesa gear 22 on a longie tudinal propeller shaft 23, at the rear end of which is a bevel gear 24 meshing with two bevel gears 25, 26 which are loosely mounted on the axle 27 of the traction wheels 13. The central portion of the axle 27 is provided with a squareportion 28 on which is slidably mounted adouble toothed clutch member 29 lee - in driving the carriage backward. The position of the clutch member 29 is controlled by a clutch lever 32 projecting upwardly through the platform 11.

The steering wheels 14: are journaled-in yokes 33 at the lower ends of vertical shafts 34. Arms 35 at the upper ends of these shafts are connectedby a link 36'to an arm37 on a steering post 38 which extends upwardly from the platform 11. A steering wheel 39 is connected to the steering post 38 through reducing gears 40. I

It will be understood that the parts thus far described provide means formoving andsteering the carriage 10 under thecontrol ofanoperator' standing on the platform 11 of the carriage. 1

Grinding drums 50, are mounted at opposite ends of the carriage 10. Each drum consists of a hollow metal cylinder'provided with an abrasive surface. In order that the drum may tilt, as well as revolve, without placing a strain on the other parts,,th'e shaft 51 of the drum 50has its-ends journaled by means of self-aligning ball bearings 52 in the outer-ends of a pair of arms 53, 53"whose inn'er' ends are attached to opposite side flanges ofthe carriage near the middle of the carriage bymean s of pivots 54L, 54:. The pivots 54, 54 areso locatedthatwhen the wheels 1 3 andzla' of the carriage andth'e drum 50 rest upon a ho'rizontalsurface the arms 53, 53 .are horizontal; Thelength of each of the arms 53, '53 is several times as I great as the radius of the drum 50. In order to strengthen the construction without inter fering with independent up and downmovements of the arms 53, 53, the arms are con nected just inside the inner side of the drum 5O by means of "a tie rod 55 containing a universal joint 56. i I The grinding drum 50" is mountedonv arms 53, 53* which are arranged in the same manner as thearms 53, 53 previously described.

Means are provided to permit an'operator standing on the platform 11 of the machine to regulate the 'pressu-reebetween the grinding drums and the floor, and also to raise the drums clear of the floor so that the machine may be moved about without grinding when desired. Such means include two pairs of levers'57, 57, 57 57 lying just inside the side flanges 12, 12 and secured to these flanges by pivots 58. The levers 57', 57 carryv at their outer ends blocks 60, 60 containing vertical holes. Tension rods 61, 61 fit loosely in the holes inthe blocks 60, 60 and have'attheir upper ends enlarged heads or nuts 62 resting on the upper surfaces of the blocks 60, 60. The lower ends of the tension rods 61, 61 are secured in blocks 63, 63 mounted on the tie rod 55 inside the planes of the side flanges and at oppositesides of the universal joint 56. Compression springs 65,65 surround the t'ension rods' 61, 61 so that they may react between the blocks 60 and 63 and the blocks 60 and 63 respectively. Similar parts, correspondingly numbered in the drawings, are provided at the outer ends of the levers 57 3 57 j 7 It is apparent that if all the levers 57, 57, 57 57 are tilted so as to move the blocks at their outer ends downward, each spring 65 is compressedso as tourge each endof each "grinding drum against the floor more, and

Such movements of the levers 57, 57, 57?, i

57 are obtained by manipulation of a foot pedal 7 O pivoted at 71011 a standard 72 secured to the upper surface of the platform 11. The rear or heelend of this pedal has a pin and slot connection73 with the rear end of a forked lever 74 mounted in bear-. ings 75. The front ends of the forked lever 74 are connected to .a cross-bar 76. Links 77, 77 extending through holes in theplatform'll have "their upper-ends pivoted on the cross bar 7 6 and have at'their. lower ends pin and slot connections 78 with the inner ends of the levers 57, 57, and 57, 57, respectively. j 1

V] hen the foot pedal is allowed to stay in its normal position, shown in full lines in Fig. 5, the grinding drums 50, 50 rest upon the floor, by their own weight. Whenthe reanend of the foot pedal 70 is depressed, for example, to the position shown in dotted lines in Fig. 5, the inner ends of the levers 57, 57 57, 57 are raised so that the outer ends of these levers compress the springs 65, 65, 65, 65 causing the springs toforce the grinding drums against the floor with pressure in addition to that of their own weight. The amount of this additional pressure may be regulated by'the amount to which the rear end of the foot pedal is depressed.

When the front end of the foot pedal 70 i rods 61, 61', 61 61 and lifting the grinding drums off the floor into an inoperative position. A spring catch 79 cooperating with the foot pedal 70 may be provided for holding the drums-in inoperative position.

' The grinding drums 50 and 50 are rotated in opposite directions by power transmitted 17 and 20 by means to them from the shafts of chains 80, 80.

r The dust produced by the drums ingrind- 7 arms 53, 53 and 53 53 respectively, by

strips of sheet metal 87 which bend so easily that the pans do not interfere with the independent up and down movement of the two arms of each pair. The dust is drawn from the pans 82, 82 by a suction blower 83 driven by the motor 15, and is deposited in a bag 84:. A pipe 85 connecting the pans with the blower has flexible portions 86, 86 at its lower end so as not to interferewith free movement of the arms 53, 53, 53 53 The attachment of the dust pans to the arms which carry the grinding drums has the advantage of raising the dust pans from the floor when the drums are raised by depressing the front end of the foot pedal 70. It is therefore possible to place the dust pans so that they lie very close to the floor when the drums are in an operative position.

It should be noted that because of the use of the tie rods and 55 and the positioning of the tension rods 61, 61, 6?, 61 and springs 65, 65, 65 65 to cooperate with these tie rods inside the side flanges 12, 12, no part of the machine projects beyond the side flange 12 at the right hand side of the machine or beyond the right hand ends of the grinding drums, except the arms 53', 53 These arms are made of flat bars located in a vertical plane so that they project only slightly beyond the side flange 12 and the ends of the drums. Consequently the machine is capable of operating upon a floor close to a wall, as clearly illustrated in Fig. 2.

What we claim is:

1. In a floor surfacing machine having a carriage and a rotary grinding drum, a pair of normally horizontal arms pivoted independently to the carriage at their inner ends and free to tip with respect to the carriage and to each other during the operation of the machine, self-aligning bearings at the outer ends of the arms, and a shaft secured to the grinding drum and journaled in said bearings, the length of each of the arms being several times as great as the radius of the drum.

2. A floor surfacing machine comprising a carriage, a grinding drum located at one end of the carriage and having one of its ends in substantially the same vertical plane as one side of the carriage, a pair of straight flat arms turned in a vertical plane having their inner ends pivoted to the carriage and carrying the drum at their outer ends, a tie rod connecting said arms just inside the drum, and a'spring located within the carriage and reacting against said tie rod to urge the drum downwar 3. A floor surfacing machine comprising a at one end thereof, self-aligning hearings in the outer ends of said arms, a grinding drum mounted on said bearings, a tie rod connecting said arms just inside the grinding drum, a universal joint in said tie rod, a pair of compression springs mounted to exert downward pressure on said tie rod at opposite sides of said universal joint, and vertically movable abutments for the upper ends of said springs.

4. In a floor surfacing machine having a carriage and a grinding drum, a vertically movable mounting for the grinding drum, a tension rod secured to said mounting and extending upwardly therefrom,a head at the upper end of said tension rod, ablock slidably mounted on said tension rod, a compression spring surrounding said tension rod to react between the drum mounting and said block, means for moving said block downward to compress the spring and for moving said block upward to raise the tension rod and mounting.

5. In a floor surfacing machine having a carriage and a grinding drum at one end of the carriage, separately vertically movable mountings for the twoends of said grinding drum, a pair of independent levers pivoted to the carriage on aligned pivots, independent compression springs reacting between the outer ends of said levers and points of the drum mounting near the two ends of the drum, and common operating means for sald levers engaging their inner ends and arranged to move their inner ends simultaneously and equally.

6. In a floor surfacing machine having a carriage and grinding drums at opposite ends of the carriage, vertically movable mountings for said grinding drums, four levers independently pivoted to the carriage, four independent springs, each of which reacts between the outer end of one of said levers and a point of one of the drum mountings near one end of one of the drums, and common operating jmeans for moving the inner ends of each of the four levers simultaneously and equally;

7. In a floor surfacing machine having a carriage and a grinding drum, independent vertically movable mountings for the two ends of the drum, a dust pan located closevto' the drum, and a flexible connection between each end of the dust pan and one of the drum mountings so that the dust pan does not interfere with independent movements of the ends of the drum. i

,In testimony whereof we have hereunto set our hands. 7 GUSTAV JACOBSON. GUNNAR F. ERICSON. 

